A sea level Golden Horseshoe nominee*

October 14th, 2012 by gavin

This is referenced to an actual report from the Australian Bureau of Meteorology about the “South Pacific Sea Level and Climate Monitoring Project” (SPSLCMP), dated November 2006. Now we are getting somewhere!

There are some obvious signs of confusion in the Gray/Cameron statements. Firstly, the Australian National Tidal Facility (which installed and monitored the tide gauges starting in 1991) used to be managed by Flinders University in Adelaide – but the facility was transferred to the National Tidal Centre run by the Bureau of Meteorology … in 2003!

Second, the SPSLCMP has been rolled out in stages starting in 1991: the third stage terminating in Dec 2005 – and they are now in stage IV. This might be the source of Gray’s claim that the project had been abandoned, though even the report he cited clearly states that the phase IV was started in January 2006 and was slated to continue at least another 5 years (at that time). The ‘last 16 years’ is a clue that the Cameron statement was obviously written in 2007 not 2012.

Finally, annual reports from SPSLCMP are available through to June 2011 – indicating a project that is very much ongoing and one that was not ‘abandoned’ before 2007.

So none of the statements that Gray (and Cameron) made about the project itself were true (either in 2007 or in 2012). But what about the sea level trends?

This is even odder. The report Gray cites states clearly that relative sea level trends (1992/3/4 to 2006) at all stations were positive (2.7 to 8.1 mm/year for the 11 of the 12 stations with long enough records). The 12th station at FSM was only installed in 2001 and the trends were very noisy (though positive). The Jun 2006 SPSLCMP report goes further and applies corrections for platform movement and the inverted barometer effect, concluding that trends ranged from 1.7 to 7 mm/year at the 11 longer stations. Note that these trends may include a component of subsidence/uplift of the islands themselves and so are the numbers most relevant for local planning (not eustatic sea level change). But so much for not finding a trend!

As one would expect, monitoring has continued since 2007, and in the latest report (June 2011), the 11-station trends range from 2.8 to 7.7 mm/year (and +17.0 mm/year at the FSM station). The monthly data series are available here for people to check for themselves. Comparisons with the satellite altimeter records show a reasonable coherence since the West Pacific sea level has risen faster than the global mean (at least partially related to the number of recent La Niña events).